Blocking the interaction between the programmed cell death (PD)-1 protein and one of its ligands, PD-L1, with blocking antibodies provides significant clinical benefits to cancer patients. To improve the clinical benefits of PD-1 blockade, we need to elaborate therapeutic strategies to counteract the tumor-intrinsic and tumor-extrinsic mechanisms of tumor-induced T cell dysfunction in the tumor microenvironment. Here, Dr. Zarour will present the data supporting the rationale for dual immune checkpoint blockade to improve the clinical benefits of PD-1 blockade in cancer.